The Influence Of Insig2 On The Differentiation Of 3T3-L1 In Different Concentration Of Glucose And Free Fatty Acid

Objective:To observe the influence of insulin-induced gene2 (insig2) on the differentiation of 3T3-L1 in different concentration of glucose and free fatty acid,and to explore the effect of insig2 in the differentiation and formation of adipocytes and lipogenesis.Method:The 3T3-L1 cells and the pcDNA3.1(+) cells and the pcDNA3.1(+)-insig2 cells were induced to differentiate in high glucose concentration(25 mmol/L GS)(with or without oleic acid(0.5 mmol/L OA)) and low glucose concentration(5.6 mmol/L GS)(with or without oleic acid(0.5 mmol/L OA)),respectively.After differentiation,the differentiation of three kinds of cells was examined by Oil Red O straining, and the expression of insig2 mRNA and adipocyte fatty acid-binding protein2(aP2) and sterol regulatory element-binding protein(SREBP) mRNA was examined by RT-PCR.Result:After differentiating in the high concertration of glucose,it was observed that there were no significant difference in the Oil Red O straining and the expression of aP2,insig2 and SREBP mRNA of the conspecific cells(P＞0.05),no matter the culture medium was add in oleate or not;After differentiating in the low concertration of glucose,it was observed that the Oil Red O straining and the expression of aP2 or insig2 or SREBP mRNA were significant different in the conspecific cells, depend on the culture medium was add in oleate or not(P＜0.05);the Oil Red O straining and the expression of aP2 or insig2 or SREBP mRNA of those cultured in oleate-free culture medium were significant decreased (P＜0.05),compared to another.The insig2 was consistently high expressd during all the differentiation and the expression of the Oil Red O straining and the expression of aP2 or insig2 or SREBP mRNA were significant decreased in the pcDNA3.1(+)-insig2 cells(P＜0.05),compared to the contrast two kinds of cells.And there was no significant difference between the contrast two kinds of cells in the Oil Red O straining and the expression of aP2 or insig2 or SREBP mRNA(P＞0.05).Conclusion:Both high concertration of glucose and free fatty acid can increase the differention of 3T3-L1,while low concertration of glucose or free fatty acid is not benefit to the differention of 3T3-L1;the expression of insig2 in 3T3-L1 is connect with the degree of the differention of 3T3-L1 and the concertration of glucose or free fatty acid in the inducing surroundings;overpressed insig2 may have a depressant effect on adipocyte differentiation in any of the four inducing surroundings,but not block the lipid synthesis completely.